I love the D100 rule system, and have been running a few mini-campaigns using Legend for the last 3 years or so. I also love the World of Greyhawk - so I've recently kicked off a new campaign set there, and started the players off with Keep on the Borderlands combined with a modified (history) version of In Search of the Unknown. My ultimate goal is to, eventually, run them through the Temple of Elemental Evil.

I haven't really struggled so far, since there is a lot of opportunity for PCs to return to the Keep to resupply and rest. The question I have is linked to the Outer Planes and using them in Legend, and how to best handle this? One of the players (a young sorcerer) has a demonic patron and I'd love to incorporate a trip to his realm at some point - as a sort of high point. The realm is a frozen wasteland which is something I can handle, based on the rules, but the sorcery used to travel to and from the realm is where I'm coming up short.